Hi everybody, as Pat, I am surprised that this thread got so emotional. However, the topic itself is still very interesting, so I would like to add mixed comments (ignoring all "irritated" / "communist" questions).
My mail is a bit long, but also tries to summarize what I want to say about this quickly growing thread. Unless you feel like you have to reply to all of it, maybe just reply to parts, or not ;-) As Scott wrote, disks with large hardware sectors typically still show 512 byte sectors to the BIOS. I would say that some cache and partition tuning (see FORMAT /A topic recently) can help with the performance loss due to the mismatch between large hardware sector size and small standard BIOS sector size. Even if the BIOS makers eventually drop the whole 512 byte based int 13 interface or drop BIOS and support only newer APIs, a DOS still only needs some sort of wrapper to keep working as long as CPU and VGA stay PC-similar. The reason to use large sectors are, as for example Jack wrote, in part to squeeze out more profit. Same for SATA and PCIe, those get same or even more speed with fewer wires as wires and pins "cost". Having more data density - both with magnetic disks and flash - is a reason why people put more ECC for larger sectors and hope that errors are "spread out" enough to be able to fix 1 with the other. Having larger, more "massive" / error resistant bits on chips or platters is no real option but messing with errors compensation is of course playing a profit game on the back of the customer, too. The story of AHCI is a bit different - from what I hear, it is needlessly bloated even when you acknowledge that having NCQ to play with queues of concurrent data streams is neat for systems with a focus on multitasking, ie. most operating systems today. Luckily disk controllers still have a SATA / IDE compatibility mode but it can happen to us that this is dropped, like "SB16" mode as soon as AC97 and HDA became sufficiently popular. They also had their pro (more channels) and used that to "win" even though they also have their cons (dumb audio / more CPU load). Or take USB versus parallel port, although I must say I am happy that we have USB sticks, webcams, scanners and printers now while of course parallel port or SCSI attached versions of those exist. Imagine you would need 5 parallel ports to plug all your gadgets. On the other hand, I suggest to buy PCI or PCIe parallel / serial port cards now, in case you later want those ports on a mainboard where somebody saved 50 cents by no longer putting those ports... They are still nice for all sorts of raw I/O without huge protocol stacks around them. Write a byte to an I/O port and 8 pins have it. It is interesting to read the specs of Jack's computer: Harddisk, CD/DVD, floppy, serial port 56k modem, no USB / FireWire, 17in CRT, single core AMD 3000, 120 MB disk. I would guess that this computer has PCI and would run great with a 5$ PCI RTL8139 network card with 100M speed tag even in DOS so I disagree about that point - ISA is very straightforward but PCI is also good, it has much more clean "plug and play" functionality compared to what people added to ISA. For the 120 MB disk, this must be very old by now? Or is it 120 GB? And yes I have heard about that MacPlus to 2007 Athlon64 comparison and it is sort of sad how software managed to waste all the extra speed while in the end you can just do the same, e.g. write texts. Finally about two other Zbigniew topics: You should not use 2 GB FAT16 partitions, those still have very large clusters. Better use FAT32 partitions of "only a few GB at most" if you want to have a system with small clusters. Of course the FAT might be bigger then. The www.colorforth.com/ide.html summary of how to access IDE disks was fun to read, although it seems that Forth is almost as obscure as ASM. Probably the reason why even BIOSes now contain Forth ;-) > bsy 1f7 p@ 80 and if bsy ; then ; > rdy 1f7 p@ 8 and if 1f0 a! 256 ; then rdy ; > sector 1f3 a! swap p!+ /8 p!+ /8 p!+ /8 e0 or p!+ drop p!+ drop 4 * ; > read 20 sector 256 for rdy insw next drop ; > write bsy 30 sector 256 for rdy outsw next drop ; Regards, Eric ------------------------------------------------------------------------------ Forrester Wave Report - Recovery time is now measured in hours and minutes not days. Key insights are discussed in the 2010 Forrester Wave Report as part of an in-depth evaluation of disaster recovery service providers. Forrester found the best-in-class provider in terms of services and vision. Read this report now! http://p.sf.net/sfu/ibm-webcastpromo _______________________________________________ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
